10x9-cost-reliability

Use this skill when a conversation involves setting, challenging, or justifying an SLO target and the cost of achieving it has not been made explicit. The canonical trigger is a leader or stakeholder demanding a high-nines SLO ("we need five-nines") without having modeled what that actually costs. The skill translates the abstract SLO number into an economic argument: each additional "9" makes the system 10x more reliable but costs roughly 10x more to deliver. WHEN TO CALL: - Someone proposes a specific SLO level (e.g., "99.999%") without a cost justification. - A team is debating whether to upgrade from 3-nines to 4-nines and needs a framework to evaluate that decision. - Leadership is treating high reliability as a prestige signal rather than a cost/benefit question. - An engineer needs to push back on an unrealistic SLO mandate from above. - A cost-of-reliability conversation needs a quantitative anchor.